Pontiac: radiator cooling fan on/ off switch, radiator cooling fan, coolant temp

Question
1992 camaro rs w/305 cu.in. v8. My question is the electric cooling fan won't go on to cool down the engine. when i turn on the a/c, the fan goes on. Is there a sensor or switch located somewhere that is keeping this fan from going on? or maybe a fuse or relay is blown out ........thank you for any help you can offer.

Answer
For normal fan operation, the coolant temp sensor sends a signal to the PCM which when the temp reaches about 109* C, the PCM grounds the fan relay and the fan turns on.
Now in AC mode of operation, as soon as the AC is turned on, the PCM grounds the relay and the fan turns on.
Your problem is either the coolant temp sensor, PCM, or the wiring in between the two.